async function async1() {
    console.log('async1 start')
    await async2()
    console.log('async1 end')
}
async function async2() {
    console.log('async2')
}
console.log('script start')
setTimeout(function () {
    console.log('setTimeout')
}, 0)
async1();
new Promise(function (resolve) {
    console.log('promise1')
    resolve();
}).then(function () {
    console.log('promise2')
})
console.log('script end')
// script start async1 start async2 promise1 script end async1 end promise2 setTimeout
